An arrangement for controlling the driving speed in a motor vehicle is already known from German patent publication 4,123,110. Here, the motor vehicle is equipped with a drive unit in addition to a power actuating member and a brake. The arrangement includes a device to which signals are supplied for a desired speed selectable by the driver as well as signals for a safety-based desired speed. The signals for a safety-based desired speed are obtained by means of a distance sensor which detects the distance to obstacles disposed ahead of the vehicle and especially a further traveling vehicle. These signals are supplied to the device for selecting the lowest desired speed as the instantaneous desired speed and for obtaining actuating signals for the power actuating member or the brakes when there is a deviation between the actual speed and the instantaneous desired speed. Signals, which are generated in traffic guiding devices external to the vehicle for permissible maximum speeds, are also supplied to the device as a permissible desired speed.
Furthermore, signals, which consider the friction contact between the vehicle wheels and the roadway, can also be supplied to the vehicle for subsequent reasonable maximum speeds, that is, desired speeds conditioned by the coefficient of friction. The device is designed to select the smallest of these desired speeds as the instantaneous desired speed.